With most airlines charging baggage fees, you see more and more people cramming whatever they can into carry-on luggage to avoid the charges, and delay retrieving their bags upon arrival. Aside from the crazy amount of time it seems to add to getting everyone seated while they stow their bags, it has added a new dimension: in-cabin theft from carry-on bags.

Now it’s not a huge problem, but it certainly is something you should be aware of because it can and does happen. Here are a few tips to help you minimize your risk of losing something valuable while you’re relaxing (or snoozing) onboard:

Wait to walk through security: If you’re stuck in a long line at security, don’t put your valuables on the conveyor belt at the X-ray scanner until you’re ready to walk through the metal detector. You don’t want your valuables sitting at the end of the belt while you’re waiting to make it through the line.

Your jacket or coat: Do you hang your coat up in the closet when flying business or first class? Common sense will tell you not to leave anything valuable in it if you do. It’s awfully easy for someone else to search your pockets under the pretense of getting something from their coat.

Mark your bags: Bags look so much alike these days that it’s hard to tell the difference. Put something on yours that is quickly and easily identifiable – a large tag, a colorful ribbon, anything that’s unique. This will make it a lot harder for someone to intentionally – or unintentionally—walk off with your luggage.

Lock your bags: It can be a bit of an inconvenience for you if you get things from your carry-on during flight, but we recommend that you lock your bag. Then, if you’re asleep or leave your seat to use the restroom, you don’t need to worry about someone getting into your bag.

Make it harder to open your bag: Place your bag upside down when you put it in the overhead. That will make it tough for anyone to open your bag without removing it from the compartment. (Most thefts are from outside pockets or directly inside the main zippered compartment.)

Stow your bag near your seat: Are you one of those passengers who likes to place your carry-on in one of the first bins in the plane (even though you’re seated mid-plane or in the back) because you think it helps you deplane more quickly? Now when the plane has landed, visualize an observant thief up front who grabs your bag and disappears while you’re trying to make it to the front. That won’t happen if you keep your bag near you!

Bags under your seat: Do you place yourpurse or small carry-on under the seat in front of you? All the same rules apply. Don’t face pockets forward where someone in front could access your bag. And if you’re traveling alone, don’t leave any valuables there when you use the lavatory or take a walk down the aisle.

Use your head: Keep your purse zipped up (or clasped) and keep your wallet out of your back pocket. It’s just common sense. There are a lot of distractions when you’re flying today. Don’t let safety get lost in the shuffle.

Say something – nicely: As we noted earlier, so many bags look the same that mistakes do happen. So don’t overreact if you find someone handling your, but do speak up immediately and firmly.

OK. You took all the appropriate precautions. And still, you couldn’t find any space for your bag and the flight attendant moved it far away from your seat…or worse, had to gate check it for you. So be ready for the worst-case scenario (lost or stolen luggage) and keep these items that are tough to replace “on your person”:

Your wallet (ID, credit cards, cash)

Your cell phone

Essential medications

Your return airline ticket (if that applies)

A final thought: When it comes to things like irreplaceable jewelry, watches, and the like: if you don’t intend to wear it every day, leave it at home in a safe or in a safety-deposit box. It will give you peace of mind.